Color reproduction is known in the art. When color artwork is prepared for subsequent printing, it is separated manually or photographically into red, yellow, and blue components and photographically broken up into tiny dots of varying sizes depending on the intensity of the red, yellow, or blue in the original. Such photographic reproductions are termed halftones. Printing plates are then prepared with these halftones, and the reproduction is printed with red, yellow, and blue ink corresponding to the red, yellow, and blue components of the original art.
Also known in the art of halftone photography is that the halftone reproductions should have dot free areas corresponding to the non-colored areas of the original art, whether red free, yellow free, or blue free, or any combination thereof. To obtain those dot free areas, while still holding dots in the lightest tones of the colored areas is quite difficult, and often requires, among other techniques; hand masking, the use of special optical filters, or double exposing (one exposure with, and one without the halftone screen).
Further, photographic halftone reproduction of colored art copy containing red and yellow colors and combinations thereof has not been possible heretofore by a Helium Neon Laser Camera because the camera is capable of photographically reproducing onto photographic film or paper only gray and blue color tones. This obviously limits the use of this camera, because it is incapable of transferring all colors to film.